It’s easy to assume that open source and multimedia are mutually exclusive. A common criticism of free desktop Linux distributions, such as Ubuntu, is that they lack support for multimedia playback, even for common formats. But don’t blame the distributions’ packagers. A maze of patents has accumulated around multimedia through the years, covering every aspect of playback and encoding. Even the MP3 format is restricted by patents that conflict with the requirements of free software licenses.

Independent developers haven’t been ignoring multimedia, however -- far from it. A number of open source projects not only manage to skirt the restrictions of existing technologies, but also improve on them.

For example, Ogg Vorbis is an open source “lossy” audio compression technology. As does MP3, it doesn’t retain every bit of data but reproduces a signal that sounds more or less like the original. But Vorbis uses advanced psychoacoustic modeling to deliver better sound quality than MP3 at a similar level of compression. What’s more, it is not encumbered by patents and is completely royalty free.

For video, look no further than the Dirac project, sponsored by BBC Research. Although still experimental, Dirac uses wavelet compression, an advanced mathematical technique that in theory should deliver better quality video than current methods. BBC owns some patents on the Dirac code, but it has granted perpetual royalty-free licenses to anyone who wishes to use them. Similarly, On2 Technologies has granted a perpetual license to its VP3 compression codec, which has become the basis of another open source project, Theora .

But while development of open source multimedia technologies proceeds apace, adoption is another matter. Vorbis is a mature codec that delivers superior performance, but few device manufacturers support it, despite the fact that it requires no licensing fees.

The problem is content. Hardware makers will support the formats that content providers offer, and increasingly that means formats that support DRM (digital rights management). Unfortunately, whether it’s Apple, Microsoft, Sony, or another company, proprietary DRM effectively makes the technology provider the gatekeeper for the entire multimedia stack. This, too, is a challenge that open source can answer.

The Open Media Commons , sponsored by Sun Microsystems, is an attempt to develop DRM technology through community participation. At its core is open source code than Sun has taken pains to ensure does not run afoul of any existing DRM patents (an area nearly as treacherous as multimedia itself). The hope is that a fully open DRM scheme will allow customers to use DRM-restricted content in approved ways across a range of interoperable software and devices from various manufacturers.

The common theme of all these projects is that cooperation and collaboration will accelerate adoption of digital audio and video, even as it pushes the technologies forward. Patent restrictions and proprietary code have held back multimedia long enough; the way ahead is open source.